1. Field of the Invention
The present invention relates to a surgical sponge, and more particularly, to a surgical sponge or similar absorbent article having associated therewith a radiopaque marker that produces a visually distinctive shadow on an x-ray image of the sponge, rendering the sponge easily detectable and locatable within a surgical patient.
2. Description of the Prior Art
During the course of a surgical operation it is generally necessary for articles, such as surgical sponges, gauzes, instruments and the like, to be placed into a wound cavity. Sponges are often used to protect and isolate organs and tissues not directly involved in the surgical procedure; to absorb incidental blood and other bodily fluids; and to serve as aids in grasping and displacing structures to facilitate access needed to various internal regions of the patient's body.
Despite rigorous attention given to locating and removing all these items prior to completion of the surgical procedure and closure of the surgical incision, such items are sometimes overlooked and remain within the patient. When this occurs, serious consequences often ensue. The patient may suffer pain, infection, intestinal obstruction, and even death. An additional invasive surgical procedure to remove the foreign object is essential to prevent serious, and possibly fatal, consequences to the patient. A retained sponge is sometimes known in the medical literature as a “gossypiboma.” In legal studies cases involving a retained surgical sponge are frequently used to illustrate the doctrine of res ipsa loquitur (the thing speaks for itself). The severity of the problem of retained surgical implements has been recognized since the earliest days of surgery. Procedures traditionally employed to prevent post-surgical implement retention include manual search of the wound by the surgeon prior to closure and a careful accounting for all materials inserted and removed from the wound. This accounting function is customarily carried out by the operating room staff, usually the circulating nurse. Notwithstanding these precautionary measures the accidental retention of surgical implements, especially sponges and the like, continues to occur to this day with disturbing regularity, even in highly respected institutions. Surgeons and related medical professionals regard this eventuality as a major unsolved problem.
At present, physical count combined with manual search remains the primary protocol used for detecting retained surgical implements. A number of difficulties compromise the efficacy of visual searching. Surgical sponges generally become soaked with blood and other bodily fluids rendering them similar in color to normal human tissues and organs. Sponges also tend to become compacted and wadded after being moistened. U.S. Pat. Nos. 4,244,369 and 4,938,901 disclose incorporation of a reflective or brightly colored fluorescent, iridescent, or phosphorescent thread in a sponge to enhance its visibility. Other sponges, such as those suggested by U.S. Pat. No. 4,068,666, are provided with a loop or locating string that may be disposed trailing out of the surgical incision.
In addition, some approaches have been proposed that would allow overlooked sponges and other surgical items to be located by remote electronic techniques and removed before completion of surgery, but these methods have not yet come into widespread use. Even with these advances, sponges are still retained. Given the serious and potentially tragic consequences that ensue, there remains a need for a redundant method of last resort, especially one that can be carried out post-surgically.
Current surgical practice employs x-ray methods for these eventualities. Most surgical instruments are composed of metal, and are relatively easily visible on x-ray. On the other hand, sponges and other non-metallic items are virtually invisible on an x-ray, so ordinarily a radiopaque component whose presence is more likely to be detected on the x-ray is securely associated with the sponge. However, intraoperative x-rays are not routinely performed before closure of the incision for several reasons: They entail the risks that inevitably arise with the extension of operative time and anesthesia, as well as undesirable expense, inconvenience, and radiation exposure. Moreover, intraoperative x-rays generally must be obtained using a portable x-ray machine. These devices generally have a lower output than fixed, standard machines, necessitating longer exposures and resulting in inferior resolution, for example due to motion of the patient which causes blurring of the image. Postoperative x-rays, even if done with a fixed machine, are still subject to some of the same disadvantages and are not routinely done unless there is a specific question or suspicion of a retained implement in a given case. Moreover, even when postoperative x-rays are obtained, retained surgical implements are still overlooked in many cases, owing to the presence of artifacts or other competing shadows on the film or the unfavorable orientation of the object relative to the x-ray incidence direction and the position of the x-ray film. The severity of the problem clearly warrants efforts that allow the aforementioned consequences to be avoided altogether by ensuring that definitive x-ray images can be obtained. It is essential that sponges be provided with a marker that may be visualized reliably and unambiguously in an x-ray image, regardless of how the sponge is handled and used during the surgical procedure. The sponge and the associated marker should not harm the patient, and should be compatible with the surgical environment and not be degraded in the presence of bodily fluids and other substances encountered during surgery.